In previous studies, we have shown that platelets from patients with the genetic disorder Glanzmann's thrombasthenia lack two membrane glycoproteins, IIb and III. We have now developed a procedure for the isolation of these two glycoproteins and have succeeded in raising antibodies against these two glycoproteins. Further studies are designed to characterize these glycoproteins and use this antisera to identify thrombasthenic individuals and carriers of thrombasthenia.